Gun-barrel-drilling machine.



F. M. CARROLL.-

GUN BARREL DRILLING MACHINE.

APPLICATION FILED FEB, 9. 1916.

Patented Dec.12,1916.

4 SHEETS-SHEET I.

F. M CARROLL.

GUN BARREL DRILLING MACHINE.

APPLICATION FILED FEB. 9. I916- 4 SHEETS-SHEET 2.

. Elwvewitoz FMWmmam %13 1 attozmeqs Patented Dec. 12, 1916.

F. M. CARROLL. GUN BARREL DRILLING MACHINE. APPLICATION FILED FEB. 9, 1916.

Patented Dec. 12, 1916 4 SHEETS-SHEET 3 F. M. CARROLL.

GUN BARREL DRILLING MACHINE. APPLICATION FILED FEB. 9. I916.

' Patented Dec. 12,1916.

4 SHEETS-SHEET 4.

' SI mveM/Itoz MWMWM 86 75%: GIIIOWQ rnnn in. cnotn, or narrow, onto; assrenon or DEE-HALF TO EDWARD S. swrrr,

QF NEW HAVEN, CONNJEGTICUT.

GUN-n a Specification of Letters JPatent.

EL-JDRILLING Macrame.

Patented Dec. 12, rate.

I Application filed February 9, 1916. Serial No. 77,147.

To all whom it may concern:

. Dayton, county of Montgomery, Uhio, have invented certain new and useful Improvements in Gun-Barrel-DrillingMachines, of

which the following is'a. full, clear, and exact description.

My invention relates to improvements in gun barrel drilling machines and has for its object to provide a simple machine for acc'urately'drilling gun barrels.

It further has for its object to provide a machine for drilling a number of gun barrels simultaneously.

It further has for its object to provide a machine in which the feed is due to hydraulic pressure'and in which the same pressure which actuates the feed also forces oil through the drill.

7 It further has for its object to provide a I machine in whichthe drilling devices are both fed forward and withdrawn by bydraulic pressure.

It further has for its object to provide a machine in which the feeding of a plurality and the supporting journal therefor.

, plungers.

of drills is accomplished by the. same hydraulic pressure and in which the feeding for drilling a plurality of barrels is independently controllable.

The following is a. description of my invention, reference being had to the accompanying drawings, in which- Figure 1 shows a generalside elevation of the complete machine. Fig. 2 shows a. partial section of the feeding cylinders and Fig. 3 is an elevation of theright hand end of the machine. Fig. 4 is a front elevation of the valve mechanism. Fig. 5 is an elevation of the left end of the machine. Fig. 6 is aside elevation of the left hand portion of the machine. Fig. 7 is a sectional. 'view through one of the barrel blank h'olggers 1g. 8 is a sectional view on the line 2z Fig. 9 showing the automatic pressure controlling valve and a section of the hand controlled valve. Fig. 9 is a section showing one of the hand controlled valves, in side elevation and the casing with the ports controlled there by. Fig. 10 shows three, detail sections of the valve body taken on the lines m-m, yy

the drill support in position, and Fig. 12 is X a perspective view of the drill support removed from the guide.

Referring more particularly to the drawings, 1 is the bed of the machine, the same constituting a tank for catching oil which is discharged. 4

2-2 are plates supporting the same. Upon the left hand end of the bed is n1ounted a housing 3 in which are journaled three barrel holding tubes or spindles each consisting of a tubular portion 4 mounted in anti-frictional bearings 55 so as to be freely revoluble. The right hand end of each tube .is provided with a nose piece 6 securely mounted thereon, in which are mounted two bushings 7 and 8, one within the other, both of hardened steel. The larger bushing 8 has a beveled opening 9 at its inner end and the smaller bushing 7 is straight and calculated to be removed when worn. The rear end of the tubular spindle 4: has a prolongation 10 of like cross section united to it by a threaded collar 10. This prolongation 10 carries at its left end a threaded hand nut 11 with an internal bevel 12. By changing the prolongation 10 for a shorter one, a shorter piece of work can be secured within the tubular spindle. Each tubular spindle is provided with a pulley 13. In the same plane as-the pulleys 13 are two idler pulleys 14 and 15, the latter being mounted upon adjustable arm 16 so that it can'be adjusted to tighten the belt 17. The belt 17 passes around one of the pulleys 13 and around the pulley 14 and then around a second pulley 13, then around the pulley 15 and then around the third pulley 13, and thence passes to a pulley upon the countershaft (not shown), as indicated in Fig. 5.

The barrel blank to be bored is placed infront end thrust into the bevel opening 9 at the nose of the spindle. The hand nut 11 is then screwed in place and tightened against the left hand end of the barrel blank whereby it is centered in the two bevels and tightly held. in place ready to be operated on by the drill-which enters the small bushing 8 at the nose of the-spindle. The ball bearings 5 are of any ordinary type.

At the opposite end of the machine and opposed to each of the revolving tubular side the spindle 1 and its properly prepared spindles 4 and axially in line with each of I them are sliding :bars. 1d ounted in a suitable housing 19 arising from the bed of the machine. As these three sliding bars are allalike it will be necessary to describe one only.

The bar 18 has a longitudinal movement somewhat greater than the length of the work to be drilled. Its rear end is of greater diameter than its forward end, thus having a shoulder 20 near its middle. From the front end back to the shoulder 20 it is pierced by a suitable oil feeding hole 21 along its axis, said hole being intersected at its rear extremity by a radial hole 22 connecting it with the surrounding chamber 23. In the nose of the bar 18 the drill 24 is mounted by any suitable means and oil entering the closed chamber 23 around the bar will enter the above described hole 21 and under pressure will flow out through the drill. Pressure-will also be exerted against the shoulder 20 on the bar and tend to force the bar 18 toward the right.

In drilling, the bar 18 is forced forward toward the revolving spindle 1. This is accomplished by means-of a small piston 25 connected to the bar 18 by the coupling 63 and which enters a chamber 26 in the casing 19, being located below the chamber 23. This small piston 25 has an end area somewhat larger than the area of the shoulder 20 with the-result that if the same pressure is applied to both cylinders, the pressure upon the small piston 25 will overcome the pressure upon the shoulder 20 and cause the bar 18 to move toward the tubular spindle with a force proportionate to the difierences between the two areas.

Both of the chambers 23 and 26 are supplied with oil under pressure. In order to control the pressure in such a way as to accomplish the movement of the bar 18 in both directions and with varying force and speed in the forward direction, I provide for each cylinder a valve 27 and a pressure plug 28,

the valves being manually controlled by handles 29 located at a convenient point. The three valves are formed in one block 30 and being similar in construction and operation it is necessary to describe but one of them.

Figs. 8 and 9 show the details of the valves. The valve casing is formed in the block 30 which is provided with an oblique channel 31 having a port 32, said channel being connected with a conduit 33 to which is connected a supply pipe 34 conducting to it oil under pressure. The valve block is also provided with ports 35 and 36. The port 35 is connected to a pipe37 which is connected to the large chamber 23 as shown in Fig. 2. The port 36 is connected to a chamber containing the lower end of the pressure regulating plug 28 which is connected to a pipe 38 which is connected to the smaller cylinder 26 as shown in Fig. 2. The valve body 27 is provided with an annular groove 39 opposite the port 32. Pressure is constant at this point and the fluid is distributed therefrom through a channel 10 in both directions. hen the channel 10 is in position to register with both the ports 35 and 36, as shown in Fig. 9, pressure is simultaneously exerted within both the cylinders 23 and 26. The valve body is also provided with a channel 41 which is spaced by 90 from the channel 40 and when registering with the port 35 connects that port with the annular groove 39. It is also provided with a central bore 12 which is intersected by a hole 13 in line with the channel 11 which hole 13 registers with the port 36 when the channel 11 registers with the port The end of the bore -12 is uncovered and when the hole 13 registers with the port 36 that port is open to a free discharge, the discharge running down behind the wall 30 into the pan formed by the base 1. The result is that when the valve 27 is in the position shown in Fig. 9 oil under pressure is fed from the channel 31 to both of the chambers 23 and26. As before explained, when pressure is so transmitted to these chambers the rod 18 will be moved toward the left because the area of the piston 25 is greater than the area of the shoulder 20. This feeds the drill toward its tubular spindle. The pressure in the chamber 23 acts to force oil through the bore 21 and out through the point of the drill so as to lubricate the drill and wash out the chips during the boring operation. valve 27 is turned 45 from-the position shown in Fig. 9 both ports 35 and 36 are closed and no action takes place. When, however, it is turned 90 from the position shown in Fig. 9 the large chamber 23 is connected with the port 32 through the channel -11 and port 35, and the port 36 is connected to discharge through the hole 43 and bore 12 with the result that, there being no pressure upon the piston 25, the oil acting upon the shoulder 20 will force the bar 18 to the right, thus withdrawing the drill from the work.

In order to regulate the force of the forward movement of the bar 18 I provide the automatic pressure plug 28 above referred to. This consists of a plug body -11 provided with suitable washers to produce a liquid tight connection between it and the valve body 30, the same being held in place by a screw nut 45. \Vithin this body is an ad- ]usting member 46 provided with engaging screw threads 47 so that it can be adjusted relatively to the plug body 4-1. It is also provided with knurled cap -18. Carried by the plug body is a valve stem 49, having a valve body 50 provided with saw cuts 51 for permitting the passage of oil under certain conditions. The valve stem 49 is provided hen the with a head 52 against which rests a spring a its increase g 53, whose lower end bears against an abutment in the adjusting member 46 so as to be adjustable thereby. The valve stem as it passes through the plug body 44 makes a,

a disk is carried on the drill, the head of the tight fit so asto prevent the passage of, oil.

When the valve body is in the position shown in Fig; 8 so as to connectthe port 36 with the pressure,'tlie valvebody' 56 is forced downward byasuchpressure so as to permit the oil to pass-through the saw cuts 51. By

adjusting the member 4L6the tension of the spring 53 can bevaried so that; the pressure transmitted through'fthe pipe 3 8; can be increased or diminished, the pr source remaining constant; W body 27 is turned so as'to-caus I to register withthe portv 36,- the-port 36 is then connected to the exhaust. nderthese conditions thefthen accumulated pressure he n'eath the valvebody 56, litts the valve body 5O partly above the port 36 so that'this port, which is then connected to exhaust, is partly open to permit the tree passage of oil from the small-cylinder 26, thus permitting the bar l8tobe t'recly retracted.

In order to keep the rods 18 from turning I provide a-Iguide bar 54 having grooves 55 as shown inlFig. 3. To the end oheach bar 18 is cla'mp'ed a bracket member 56, said members having projections which engage the grooves 55 in the guide bar and thus act to prevent the bars. 18 from turning. The brackets can :be' clamped at desired points by the screws 56". j.

-. lnvthe end of each small chamber 261s a spring buder'consisting ot a pin 57 engaged by a spring 58. When the bar 18 is near thejendjof its stroke a portion of the meni-I.

finish the boring. These small plugs are 10- cated directly beneath the large cylinders 23 and on two side members 56 T-providedownward extensions 59 for engagthe corre-Z spending spring bufi'ers 57. 66 is a drain pipe extending from the pan 1 to the supply'reservoir from which 1t is again pumped through the pipe 34.

Thedrills 24: being necessarily long and slender it is necessary to support them when ing the bar 18 and its plunger 25, the same being'shown in one instance in dotted lines hi 11.

6 4i is a loose disk which fits the round portion of the keyhole slot and is provided wlth 2 a hole torthe drill. This supports thedrill at the beginning of the boring and during the first part of its work. When, however, the head ofthe bar 18 reaches the disk 64: it'forces it out of its seat whereupon the bar together with the yoke 63 passing through the keyhole opening 62.

The operation of my machine is simple x and is readily understood from the forego- 'dle 29 correspondingfto the bar 18 opposite the spindle containing the gun barrel just referred; to, is thenturned upward so as to place the channel 40 in the position shown in Fig. 9 connecting both cylinders 23 and 26 with pressure. This'pres'sure acting upon the plunger 25 feeds the bar 18 forward, oil from the cyli nder',jbeing discharged through the point of the drill 24. When the boring is nearly completed the clamp 56 en-- gages the spring bufier 5T so-as to yieldingly resist the motion of the bar 18. When the drilling operation is completed, the valve 27 is turned to an angle of 90 so as to connect the channel ll with the large cylinder through the port 35 and so as to connect the small cylinder withe'xhaust through the hole 4L3 and bore 42 with'the result that the pressure of the oil acting upon the shoulder 20 retracts the bar 18. When the bar 18 has been fully retracted the valve 27 is turned to a neutral position and a new barrel blank is replaced for the one which has just been drilled. During the forward movement of the bar 18 the pressure in the small cylinder is controlled by the pressure plug 28 which has been adjusted to give the desired reduction in pressure and the drill is supported by thedisk 6-1 in the support 61 until such support is no longer necessary, after which the disk 6-t is carried along on the drill. Each otthe bars 18 is independently controllable by itsvalve 27. Uil is fed thorugh the drill when the drill bar is moving in both directions acting at all times that the drill is moving to wash out chips that may be in'the bore.

As will be evident to those skilled in the art, my invention permits of various modifications without departing from the spirit thereof or the scope of the appended claims.

at l[ claim is 1. ltn a machine for drilling gun. barrels and the like, the combination: of a longitudinally movable drill-holding-bar having a longitudinal oil duct, therein, ot a cylinder surrounding said bar and a source of fluid pressure acting to-simultaneously move said bar and teedfluidthrough said duct to the I drill.

2. Tn a machine for drilling barrels and the like, the combination of a longitudinally movable drill-holding-bar having a longitudinal oil duct therein, of a cylinder surrounding said bar and a source of fluid pressure acting to simultaneously move said bar in one direction and feed oil through said duct to the drill, a second cylinder, a plunger therein connected to said bar and means for causing said fluid-pressure to act upon said plunger to move said bar in the opposite direction.

3. In a machine for drilling gun barrels and the like, the combination of a longitudinally movable drill-holding-bar having a longitudinal oil duct therein, of a cylinder surrounding said bar and a source of fluid pressure acting to simultaneously move said bar in one direction and feed oil through said duct to the drill, a second cylinder, a plunger therein connected to said bar and means for causing said fluid pressure to act upon said plunger to move said bar in the opposite direction, a valve controlling ports to both of said cylinders so that the cylinder containing said bar is always subjected to pressure when said bar is moving in either direction, one of said cylinders only being subjected to pressure from the source when said bar is moving in a rearward direction.

4. In a machine for drilling gun barrels and the like, the combination of a longitudinally movable drill-carrying-device, said device having a longitudinal oil duct substantially in line with said drill, and being provided with two piston surfaces facing in opposite directions, of a casing surrounding said-device and means for supplying fluid pressure to both of said Surfaces when said bar is moving in the forward direction and to one of said surfaces only when said bar is moving in the opposite direction, said pressure when the bar is moving in the forward direction acting to move said bar and simultaneously feed oil to the drill.

5. In a machine for drilling gunbarrels, the combination of a longitudinally movable drill-holding-bar, having an oil duct substantially in line with said drill, said bar having a shoulder at its approximate center, a plunger connected to said bar and parallel therewith, cylinders surrounding said bar and said plunger respectively, the end of said plunger facing in the opposite direction from said shoulder, a source of fluid under pressure and means for connecting said source to both of said cylinders simult-aneously and at other timeswith only the cylinder surrounding said bar.

6. In a machine for drilling gun barrels and the like, the combination of a longitudinally movable drill-holding-bar, of a cylinder-surrounding said bar and a source of fluid pressure acting to move said bar, a'

bracket'on the rear end of said bar, and a stationary guide rod engaged by said bracket so as to prevent said bar from turning.

T. In a machine for drilling gun barrels and the like, the combination of a longitudinally movable drill-holding-bar, of a cylinder surrounding .said bar and a source of fluid pressure acting to move said bar, a bracket on the rear end of said bar and a stationary guide rod engaged by said bracket so as to prevent said bar from turning, said bracket being longitudinally adjustable upon said bar.

8. In a machine for drilling gun barrels and the like, the combination of a longitudinally movable drill-holding-bar, of a cylinder surrounding said bar and a source of fluid pressure acting to. move said bar, an extension on the rear end of said bar, means for preventing said bar from turning, and a 5 rin bufi'er en a ed bv said extension" I: D C a when near the end of the forward strokeiof said bar.

9. In a machine for drilling gun barrels and the like, the combination of a horizontal longitudinally movable drill-holding-bar, a drill carried thereby. a revolving workliolder located at a distance from said bar and in, line therewith, a support located between said workholder and the forward end of said bar and a removable drill-guidinglnember carried by said support and adapted to be removed from its seat when engaged by the forward end of said bar.

10. In a machine for drilling gun barrels and the like, the combination of a longitudinally movable drill-carrying-device, said device having a longitudinal oil duct substantially in line with said drill, and being provided with two piston surfaces facing in opposite directions, of a casing surrounding said device and means for supplying fluid pressure to both of said surfaces when said bar is moving in the forward direction and to one of said surfaces only when said bar is moving in the opposite direction. said pressure when the bar is moving in the forward direction acting to move. said bar and simultaneously feed oil to the drill, and a plug for automatically controlling the pressure upon the rearwardly facing surface when acting to feed the bar forward.

11. In a gun barrel drilling machine, the combination of a longitudinally movable drill, a revolubly mounted longitudinal spindle in line with said drill and adapted to hold the blank to be drilled and means for revolving said spindle, said spindle having at its forward end a nose piece provided with a central opening and terminating on its inner surface in a beveled opening and having at its rear end means for forcing the blank against said beveled opening.

12. In a gun barrel drilling machine, the

combination of a longitudinally movable drill, a revolubly mounted longitudinal spindle in line with said drill and adapted to hold the blank to be drilled and means for revolving said spindle, said spindle having at its forward end a nose piece provided with a central opening and terminating on its inner surface in a beveled opening and having at its rear end means for forcing the blank against said beveled opening, said means consisting of a closure having a beveled recess facing the first above mentioned beveled portion.

13. In a gun barrel drilling machine, the combination of a longitudinally movable drill, a revolubly mounted longitudinal spindle in line with said drill and adapted to hold the blank to be drilled and means for revolving said spindle, said spindle having at its forward end a nose piece provided with a central opening and terminating on its inner surface in a beveled opening and having at its rear end means for forcing the blank against said beveled opening, said spindle consisting of forward and rearward tubular portions, bearings for revolubly supporting said forward portion, and means for removably coupling the rear portion to the forward portion.

14. In a gun barrel drilling machine, the combination of a longitudinally movable drill, a revolubly mounted longitudinal spindle inline with said drill and adapted to hold the blank to be drilled and means for revolving said spindle, said spindle having pulley.

FRED M. CARROLL. 

